Background

• Chile has one of the highest alcohol consumption in the continent\(^{[1]}\)
• In 2016, led in high school cocaine, coca paste, and marijuana use\(^{[2]}\)
• Over 170% growth in drug-related mortality, 2000 vs 2019\(^{[3]}\)
• In 2020, 6% of Chileans (12-64) had a problematic substance (alcohol & drug) use \(^{[4]}\)
• In Chile, the government funds substance use treatments (SUT) for all with public health insurance (~81% of the population)\(^{[5]}\)
• There is limited information regarding short-term, medium-term, and long-term mortality risks
• Analyzing mortality among administrative regions may reveal disparities in post-treatment outcomes
• Regional data can inform policy and resource allocation

Objectives

To describe the standardized mortality ratios (SMRs) for all adult patients in publicly funded SUT within 2010-2022, along with regional specificities

Methods

Design: a population-based retrospective cohort of adults enrolled in Chilean SUT programs (18-65) with national mortality data (2010-2020).

Analysis plan. We calculated SMRs by comparing the observed deaths vs. the expected within regions, age groups (18-29, 30-44, 45-59 & 60-65), periods (annually), and across sexes. Stratum-specific population estimates were obtained from the Ministry of Health’s mortality data, supplemented by population projections from the National Institute of Statistics’ open data portal\(^{[6]}\). Regional data on cocaine, marijuana, and hazardous alcohol use were obtained from the 2020 Chile National Drug Study by the National Drug and Alcohol Prevention and Rehabilitation Service. 95% confidence intervals(CIs) were calculated using Vandenbroucke’s method\(^{[7]}\).

Preliminary Results

Figure 1: Characteristics of SUT patients

Figure 2: Standardized mortality ratios for people in SUT, by age group and sex

Figure 3: Regional data in quartiles

The SMR in the SUT population was 15.5 (95%CI 15.0, 16.1) times higher than expected based on the general population. Women aged between 30-44 had a mortality risk up to 29.6 times (95%CI 26.0, 33.5) higher than expected.

Regions with high SMRs for men also have high SMRs for women. There were also regional variations in mortality risks post-SUT, but the regional prevalence of problematic substance use does not appear to be related to SMRs.

Discussion

• High cumulative mortality risk in SUT patients vs. general population
• Higher risk particularly among women
• Largest sex gap at younger ages
• Further exploration of substance use’s contribution to elevated risk
• Mortality risks were higher in areas influenced by ethnic and cultural barriers, discrimination, or geographical isolation, which hinder access to treatment

References

Funding sources